With growth of services, a problem that a processing capability of a server does not meet a service processing need occurs. The server needs to be upgraded at a specific interval for replacement with a part with a stronger processing capability. The server includes a large quantity of parts such as a fan, a memory, a network adapter, a disk, and a processor. All parts of the server are integrated on one mainboard. The parts have different upgrade cycles. For example, an upgrade cycle of the mainboard, the processor, or the memory is relatively short, and is usually two to three years, whereas an upgrade cycle of the disk is relatively long, and is usually five to seven years. It can be learned from a present server architecture that all the parts of the server are integrated on one mainboard. When maintaining multiple parts on the mainboard, a maintenance engineer needs to sequentially remove and insert the multiple parts on the mainboard. Consequently, maintenance efficiency is low.